// https://www.nowcoder.com/practice/75e878df47f24fdc9dc3e400ec6058ca

#include <iostream>
#include <vector>
using namespace std;

struct ListNode {
    int val;
	struct ListNode *next;
 	ListNode(int x) : val(x), next(nullptr) {}
};


class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param head ListNode类
     * @return ListNode类
     */
    ListNode* ReverseList(ListNode* head) {
        ListNode* cur = head;
        ListNode* prev = nullptr;
        while (cur) {
            ListNode* next = cur->next;
            cur->next = prev;
            prev = cur;
            cur = next;
        }
        return prev;
    }
};